This invention relates to couplers for joining flexible hoses, particularly, fluid carrying hoses employed with medical apparatus. Such apparatus can include, but is not limited to, air mattresses and water beds. The couplers can also be employed with apparatus for draining or introducing body fluids. When used in any of the above applications it is necessary that such couplers be rugged; provide a good fluid seal; be simple to use; and be easy to connect and disconnect.